Devices such as power supplies are often implemented as modules that can be placed in a device bay. When the module is seated in the device bay, one or more electrical connectors of the module are physically in contact with one or more connectors at the back of the device bay. When a connector on the module does not match a connector in the back of the device bay, this may result in the module being physically prevented from being seated in the device bay.
Sometimes modules may have identical or near identical physical form but different electrical characteristics. For example, two power supplies may have a same form factor and same connectors, but have different electrical characteristics. For example, the two power supplies may supply current at a different voltage and/or a different power level. For some applications, it may be acceptable to use either of the two power supplies despite the difference in electrical characteristics. In other applications one power supply may be acceptable while the other may not.